Continuous rod warhead



L; 26 v E May 3, 1966 P. E. CORDLE ETAL 3,249,050

CONTINUOUS ROD WARHEAD Filed April 26, 1963 2 Sheets-Sheet 1 \f /H =r='l"q- FIG. I.

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INVENTORS.

FIG. 3. PAUL E. CORDLE HIRAM. E. MOORE WILLIAM w. ALLEN f/KM ATTOR NE Y.

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CONTINUOUS ROD WARHEAD 2 Sheets-Sheet 2 Filed April 26, 1963 AH M ll l k U a c. A v

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United States Patent 3,249,050 CONTINUOUS ROD WARHEAD Paul E. Cordle, China Lake, Hiram E. Moore, Anaheim, and William W. Allen, La Mirada, Califi, assignors to the United States of America as represented by the Secretary of the Navy Filed Apr. 26, 1963, Ser. No. 276,110 7 Claims. (Cl. 102-67) The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to an explosive projectile and more particularly to improvements in expandable continuous rod warheads utilized in the field of high speed rocket propelled weapons.

In the fabrication of continuous rod warheads it has been the practice to assemble the warheads in a manner such as to provide a plurality of individual rods secured together at their ends to form a continuous rod bundle having an internal cavity for internally receiving an explosive charge. The rods may be welded together at their ends to form hinge joints in order to provide an expansionable continuous ring-like member permitting the bundle to be expanded to many times its original diameter upon detonation of the internally contained explosive charge for providing a lethal target intercepting device.

Heretofore, the rods of a given rod bundle were mounted in a manner such as to require the bundle to function both as an external skin member and as a structural component for the missile in which the warhead is arranged. Such an assembly requires that the rod bundle be secured to the missiles structural components through welded joints thereby requiring complicated, expensive, and closely controlled welding operations in order to insure a proper rod bundle release and an expansion be effected upon detonation of the explosive charge. As the individual rods of the known continuous rod warhead assemblies serve as structural components for supporting missile structural loads, it has been found that in practice the rods are often caused to undergo physical distortion as a result of the structural loads imposed on the rods, whereby the destructive effectiveness of the warhead is substantially impaired, as deformation of only a small percentage of the rods tend to significantly reduce the lethal effectiveness of the warhead.

Furthermore, prior to the present invention it has been the practice to insert a casting mold within the cavity of the rod bundle. The mold usually comprised a generally cylindrically shaped liner of suitable material so machined as to provide a constricted central portion and so shaped and dimensioned as to provide a mold for casting an explosive charge within the bundle to provide a charge of a predetermined configuration in order to impose control on explosive impulses generated along the length of individual rods of the rod bundle when detonation of the cast explosive charge occurred.

. As an alternative to the above-mentioned technique of casting an explosive charge within a liner, the explosive has, with limited success, been pressed and machined to match-fit within a constricted liner, severed at the center, and the opposite halves thereof inserted in opposite ends of the liner, aligned and reunited within the liner. This technique has not proven, in practice, to be satisfactory as it requires the use of complex, expensive and time consuming fabrication operations. The liner, as used in the known techniques, has been retained and utilized within the warhead to provide an assembly unit for aligning the explosive charge, and as was deemed necessary for providing explosive impulse control along the individual rods of the given rod bundle, to reduce severance of the 3,249,050 Patented May 3, 1966 individual rods within the bundle upon detonation of the explosive charge.

The general purpose of the present invention is to provide a unitary warhead assembly which will properly support a given rod bundle in a manner providing for a proper and effective release of the rod bundle upon detonation of the warhead and which will permit the use of simple and economic assembly techniques.

Therefore, it is an object of the present invention to provide a simple, easily assembled, dependable continuous rod warhead having a limited number of components being capable of functioning with a high degree of efiiciency.

Another object is to provide a continuous rod bundle support for insuring a proper and reliable rod bundle expanslon.

A further object is to provide a unitary continuous rod warhead assembly which may be first fabricated and then stored in an assembled state.

Still another object is to provide a method of assembling a continuous rod warhead which method is simple, efficient and economical, and which provides for a highly effective device capable of being transported and stored in an assembled condition.

Other objects, advantages and novel features of the invention will became apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a view of a rocket propelled missile provided with a continuous rod warhead, as provided for in the present invention;

FIG. 2 is a sectional view, on an enlarged scale, taken generally along lines 22 of FIG. 1;

- FIG. 3 is a partial section view of the warhead of FIG. 2, illustrating an assembly operation utilized in the present invention;

' FIG. 4 is a schematic view, on an enlarged scale, of a goption of the rod bundle in a partially expanded com mon;

. FIG. 5 is a diagrammatic view illustrating a partially consumed explosive charge having a projected shock front impinging along the rods of a rod bundle; and

FIG. 6 is a schematic view, on a reduced scale, of an expanded rod bundle.

, Referring now to the drawings, wherein like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a high speed missile 10, having as one of its components, a warhead assembly 11 positioned along the body of the missile for comprising an integral component thereof.

Turning now to FIG. 2, the warhead 11 is provided with fore and aft assembly means, illustrated as threaded members 12 and 12', which serve for mounting the warhead within the missile 10. A hollow or cavity forming cylindrical stress skin 13, formed of a suitable frangible material, such as a thin gauge stainless steel, is provided and serves as an outermost member for the assembled warhead and serves as a fairing surface therefor as well as additional functions as will hereinafter be described. The cavity of the cylindrical stress skin 13 receives in telescoping fashion a pre-assembled continuous rod bundle 14 arranged within an external rod bundle receiving cavity 15 externally formed about a vhollow cylindrical warhead case 16. The case 16 may be formed of a light weight material such as, for example, aluminum or other frangible material and serves to support the entire warhead assembly 11. The hollow portion of the cylinder 16 provides a cavity which may be closed at one end by a closure member 16' formed as a unitary member of the case 16.

The rod bundle receiving cavity 15 assumes the con figuration of an elongated external depression completely surrounding a major portion of case 16 and is bounded at each end by case encircling shoulder portions 17 and 17'. The shoulders are so formed as to protrude from the case 16 and are provided with grooves 18 for receiving ring seals 1?, arranged near the apex thereof for effecting a seal between the shoulder portions and adjacent portions of the stress skin cylinder 13 to thus establish a sealed cavity 15 with the rod bundle 14 disposed therein.

The rod bundle 14 is of a known type being formed of a plurality of individual steel rods 14', FIG. 4, pinned at hinge joints J, usually formed through a welding of the individual rods near the ends thereof so that the bundle 14 may be collapsed with the rods 14 being generally parallel and juxtaposed forming a cylinder about the case 16 and seated Within cavity 15 in a case girdling fashion. It is to be noted that in operation when the warhead is subsequently exploded the hinge joints J permit the bundle to be upset into a continuous ring, FIG. 6, which provides an expanded lethal target intercepting device.

It has been found desirable to disperse a conventional potting compound 19 throughout the cavity 15 in order to fill voids occurring adjacent the individual rods 14' of the rod bundle 14 when the warhead 11 is in its assembled condition. The potting of the rods is possible since the bundle 14 is structurally supported by the case 16 and is maintained in a collapsed condition within the cavity 15 by the stress skin cylinder 13, and since no operative structural load is imposed on the assembled bundle 14 so long as case 16 remains intact.

The hollow portion or cavity of the case 16 receives a pressed explosive charge 21 which serves to explosively upset the bundle 14 when detonated in a suitable fashion. The particular explosive composition utilized for upsetting of the bundle 14 is dictated by parameters such as the degree of friction generated heat imposed on the skin of the missile, the compression molding characteristic de sired, and the rod-acceleration properties thereof. An explosive compound which has been found quite satisfactory is plastic bonded explosive (PBXN-3) having a composition of 14 percent nylon (ZYTEL 63) and 85 percent HMX (cyclatetramethylenetetranitramine), of better than 98 percent purity, prepared by a methanol-water slurry process.

Consolidation of the compound into a cylindrical billet is accomplished through known compression molding tech niques carried out at temperatures of 245 and at 20,000 pounds per square inch with two minute dwell time. The compressed billet may be pressed, or pressed and machined, so as to provide an external contour generally conforming to an hour-glass configuration such that the diameter of the cylindrical charge is reduced progressively from points near ends thereof tapering toward the center portion of the cylinder. It is to be particularly noted that the contour of the machined billet or charge 21 is shaped to provide an air liner or chamber 22 formed about the fabricated billet in a manner such as to provide a greater volume for the chamber near the central portion of the billet 21. A booster tube opening 2 3, in the form of a longitudinally extending cavity, extends through the center of the machined billet or charge for accommodating the insertion of a booster assembly 24 having therein a safearm firing device 24' which serves to detonate a pellet 24" to initiate combustion or detonation of the charge 21. It is to be understood that the pressing, machining and drilling techniques utilized in forming the billet or charge are well known, therefore, a specific description thereof is not deemed necessary, and is omitted in the interest of brevity.

The warhead of the present invention may be completely assembled at the point of fabrication, delivered and/ or stored as ready-to-use hardware. In the assembly of a continuous warhead, according to the present invention, a case 16 is inserted into a partially collapsed rod bundle 14 so that the rod bundle may be further collapsed and caused to seat Within the cavity 15. A bundle compressing clamp 25, FIG. 3, may be provided to further collapse the rod bundle 14 to ensure its seating within the cavity. The clamp further serves to maintain the collapsed rod bundle in proper relation with the case 16 during the initial portion of the rod bundle, case and stress skin associating operation. The case 16, having the rod bundle 14 collapsed thereabout by clamp 25, is partially inserted into one end of the hollow cylindrical stress skin 13 in a telescoping fashion. The case and stress skin are then caused to be disposed in an upright condition. An upright annular cup 26, having a sealing ring 26, is provided for receiving and retaining a predetermined quantity of potting compound and is arranged about the uppermost extremity of the stress skin 13 at the telescoping portions of the case 16 and the stress skin 13, FIG. 3, in order that a predetermined quantity of conventional potting compound 19 may be introduced into the cavity 15 during completion of assembly.

For completing the assembly of the case 16, rod bundle 14, and the stress skin 13, telescoping or opposed movements are caused to occur between the skin 13 and the case 16. As the stress skin 13 and case 16, with its associated rod bundle 14, are telescoped into an assembled relationship, a natural vacuum is created Within the cavity 15 for drawing the potting compound 19 into voids occurring within the cavity 15 to thus effect a potting of the rods 14' of the rod bundle 14 within the cavity. It is understood that the band 25 is removed during the telescoping assembly operation so that the rod bundle 14 and case 16 may be properly arranged within the stress skin 13 to provide an assembled unit. The stress skin 13 may be secured in place by slightly crimping or rolling the ends of the stress skin over the shoulders 17 and 17' of the case 16 to the extent necessary for maintaining an assembled relationship.

For completing the warhead assembly, the explosive charge 21, which has been pressed, or pressed and machined, to proper dimensions, as hereinabove described, may now be inserted into the hollow cylindrical case 16. Shock absorbing charge pads 27 and 27 are utilized in aligning the charge within the case 16, along the longitudinal axis thereof, so that the aforementioned air chamber 22 is defined by the internal walls of the case 16 and the external surface of the charge 21. A locking ring 28 and a closure plate 29 are next inserted to maintain the charge 21 in place. A locking lip 30 is turned over the plate 2? in order to secure the charge 21 within the case 16.

The booster and lead assembly 24 and 24' may now be inserted into the booster tube opening 23, if found desirable instead of inserting during, and preparatory to, final assembly steps. As the assembly 24 is inserted into the opening 23, it is arranged so as to position the pellet 2 4" on the centerline of the warhead 11 halfway of the charge 21 and is secured in position by any suitable locking means, including the ring 28, FIG. 2.

After the assembly 11 is completed, it is to be delivered to the point of assembly for the missile 10, whereupon it is provided with a necessary fuze connection for the leads L which serve for detonating the pellet 24" in a desired fashion, so that in operation as a missile 10 approaches a selected target the missiles fuze causes the safe arming device 24 to detonate the pellet 24 thus detonating the explosive charge, as schematically illustrated in FIG. 5, for efiecting an impulse, designated 31. The impulse is controlled by the air liner forming configuration of the charge 21. The aforementioned impulse 31 serves to impinge uniformly along the walls of the case 16, and consequently along the rods 14' of the rod bundle 14, to rupture the case and spread the bundle 14 into a lethal target intercepting device, FIG. 6, by causing the rod bundle 14 to expand uniformly into a ring-like configuration.

Therefore, it is understood that in accordance with the above, there has been provided an elfective continuous rod warhead, and an economic, efficient, and simple method of assembly therefor.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be prac ticed otherwise than as specifically described.

What is claimed is:

A continuous rod Warhead comprising:

collapsed expandable continuous rod bundle formed of a plurality of individual rods joined at the ends thereof in such a manner as topermit the bundle to expand into a ring of generally end-to-end rods when expanded;

unitary case having an internal explosive receiving cavity and an external case girdling rod bundle cavity for receiving said collapsed bundle in a case encircling fashion;

hollow stress skin for receiving said case and said bundle in a telescoping fashion;

shaped explosive charge disposed within said case, said charge being so shaped as to provide an explosive impulse control air chamber surrounding said charge;

a charge detonating booster safe-arming means centrally disposed within said charge; and

securing means for securing the charge, case and stress skin into a unitary continuous rod warhead.

The warhead defined in claim 1 further characterized in that the securing means includes a plurality of turned edges formed on the stress skin and case.

A continuous rod warhead comprising:

a continuous rod bundle supporting case having an explosive device receiving cavity therein;

with air.

6. The warhead of claim 5 wherein a booster is included within said explosive device near the center thereof.

7. The warhead of claim 5 wherein said stress skin comprises a hollow frangible cylinder.

References Cited by the Examiner UNITED STATES PATENTS Libbey 10267 Hicks 102-68 Welanetz 10268 Adler 10267 Lieberman et al 86-1 Stresau et al 86-1 Boswell 102-67 Nooker 10267 Urdapilleta 102-67 X BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

R. V. LOTTMANN, G. L. PETERSON,

Assistwnt Examiners. 

3. A CONTINUOUS ROD WARHEAD COMPRISING: A CONTINUOUS ROD BUNDLE SUPPORTING CASE HAVING AN EXPLOSIVE DEVICE RECEIVING CAVITY THEREIN; A CONTINUOUS ROD BUNDLE SUPPORTED ABOUT SAID CASE; A STRESS SKIN SURROUNDING SAID ROD BUNDLE; AND AN EXPLOSIVE DEVICE COMPRISING A SHAPED CHARGED HAVING AN EXTERNAL CONTOUR CONFORMING GENERALLY TO AN HOURGLASS CONFIGURATION ARRANGED WITHIN SAID CAVITY FOR EXPANDING SAID CONTINUOUS ROD BUNDLE. 